The present invention refers to a mobile machine for withdrawing ballast from a ballast bed.
Mobile ballast bed machines are known which include a machine frame supported on undercarriages for movement along a track and a suction arrangement mounted on the machine frame. The suction arrangement is provided with a negative pressure generator and has a ballast receptacle with an intake port and a discharge outlet, with the intake port of the receptacle being operatively connected to a suction tube which is immersible in the ballast bed and has an inlet opening vertically adjustable and transversely displaceable by a drive unit.
A mobile ballast bed machine with suction arrangement of this type is known from e.g. U.S. Pat. No. 4,938,239. The suction arrangement has a total of three suction tubes which are spaced from each other transversely to the machine frame. Ballast withdrawn by the suction tubes is collected in a central ballast receptacle which--after being filled--is emptied. A drawback of such a mobile ballast bed machine is the decreased productivity because it does not permit a withdrawal of ballast while the receptacle is emptied.
Further suction arrangements are known from German Pat. No. DE 82 36 650 U, Swiss Pat. No. CH 451 987 B and U.S. Pat. No. 4,570 287.